[CentOS] VMWare disaster recovery?

Fri Jul 14 12:53:21 UTC 2006
Les Mikesell <lesmikesell at gmail.com>

On Fri, 2006-07-14 at 02:20, Dan Pritts wrote:
> On Thu, Jun 29, 2006 at 02:53:45PM -0500, Les Mikesell wrote:
> > I found this in the large and growing list of downloadable vmware
> > appliances: http://www.vmware.com/vmtn/appliances/directory/316.
> > I haven't run it yet, but it claims to provide a way to mirror
> > running windows boxes over iscsi to vmware disk images, then allows
> > you to boot that image under vmware as a replacement for the server
> > with little downtime.
> This really shouldn't be hard to do with linux.  it's a lot harder
> with windows since windows cares so much about the specifics of the
> hardware it is running on.

The procedure you use with windows is to install the disk driver it
will need under vmware before the copy.  Everything else will
auto-detect.  Then once it is up you install the vmware tools
which provides better drivers for the video and network. 

> The only things you need to change
> should be the initrd.  You should be able to build an initrd that
> has all the required drivers for both your physical hardware
> and vmware.

> I have more or less done this with a running debian unstable system.
> > Has anyone attempted something like this with Centos - or know if
> > software mirrors work over iscsi? 
> I haven't, but I'd be real surprised if it didn't work.

The piece that I haven't been able to match is Windows (server versions)
ability to convert a standard NTFS disk to dynamic, then add a mirror
on the fly.  If you didn't install on RAID1 to begin with and remove
one of the partitions, how do you get a working system to the point
where you can add a mirror?  You'd probably have a fair chance of
making things work with an rsync copy while running, followed by
an rsync in single user mode with databases, etc. shut down, but
what I really want is a live mirror that would always be up to date
any time the physical server died.

The SME Sever distribution will install itself on RAID1 partitions
with missing mirrors, but they had to modify the stock Centos
installer to do that.

  Les Mikesell
   lesmikesell at gmail.com